Automated Device Charging Station
AUTOMATED DEVICE CHARGING STATION |
Problem
For this project, we worked with a company that provides personal devices to inmates living in correctional facilities. These devices, in the form of smaller “phone” type devices as well as larger “tablet” type devices, allow inmates to communicate with those outside of the facility, as well as pursue continuing education from inside the facility.
As beneficial as these devices are to the inmates and facilities, a larger number of issued devices paired with the logistics of charging these devices made utilizing them progressively more difficult. In the original implementation, guards collected and manually connected each device to a cable to charge them. The ability of the guards to collect, charge, and redistribute devices with this manual procedure greatly reduced as the number of devices increased. This caused many inmates to go for significant periods without their devices. This was not only upsetting to the inmates but also decreased any revenue generated from using the devices.
This proved the need for a solution that allowed inmates to charge their own devices. This would require a self-service system to validate, charge, and secure these devices. This “automated charging station” would also need to be ruggedized to allow operation inside the facility with minimal intervention from outside personnel. Lastly, this charging station would need to interface with existing devices, inside their custom housings, to provide a charging method that can easily be retrofitted inside existing devices.
Solution
Given the requirements for this product, we began by designing a custom steel enclosure to be hung on the wall inside the facility. This required custom mechanical design and included specific design considerations to make installation and operation easier inside the facility.
We implemented a Linux-based solution to validate and secure the devices while charging. The system utilized a touch screen to “check in” a device with an inmate's custom ID and PIN. RFID readers could then be used to validate that the device being checked in is the correct device.
Once this is complete, a slot “unlocks”, and allows a device to be inserted. Once it is determined the correct device is inserted correctly, the steel enclosure slot is locked, and the device begins to charge. Later, the inmate can retrieve their device using the same custom ID and PIN.
The charging station itself also interfaces with various APIs and validates inmate credentials over Wi-Fi, as well as collects diagnostic data and handles remote updates and troubleshooting.
One of the most significant challenges was interfacing the devices to the charging stations. Because we needed to retrofit a charging method into the custom case used with the devices, we needed to use a slightly unconventional method.
We retrofitted the devices by leveraging the screws holding the case together, using them as charging rivets that make contact inside the charging station. We connected these screws to the charging port in the device through a custom flexible printed circuit board. Finally, we covered the circuit board with a custom plastic piece to protect devices from tampering.
What Set Us Apart
We believe what set us apart on this project was our ability to design a full product, including custom mechanical/electrical/software, based on a description of a problem that needed solving. For this project, we were a one-stop shop that could create exactly what the customer needed to solve their problem. We also designed this product with a significant set of restrictions (needing to be compatible with existing device cases.) Despite this, we devised a creative solution to achieve the desired functionality. Our ability to be flexible and work with the customer to update the product as new features and requirements arise also sets us apart from other embedded design firms.
Results
In the end, we were able to provide a cost-effective product to our customer and satisfy a need they had. These new charging units have opened opportunities to sell into larger facilities our client would not have been able to service before this solution.
